Apparatus and method of filling ingot molds



INVENTOR, WILLIAM M. DUNCAN,

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A TTORNEY5 W. M. DUNCAN Filed Jan. 26, 1955 APPARATUS VAND METHOD OF'FILLING INGOT MOLDS July 23, 1957 United States Paten-t APPARATUSAND'METH'OD OFFILLING INGOT MOLDS M. Duncan, Alton, Ill.

Applicationlzlanuary 26,1953, Serial No. 333,317

V-2 -Glaims. {Cl.'22"15`5) This invention "relates tomethods-'of and`apparatus for pouring ingots.

One of the principal problems confronting the industry has been that yofpreventing piping or spongy spots from occurring in the center ofingots. It will be understood that when metal poured into an ingot moldfreezes, there is a reduction in volume or shrinkage of crystallization,which ltends to produce voids in the center portions of the casting.Such voids result in structural weakness when the ingot is later Worked,as by forging or the like. Accordingly, it is an object of thisinvention to avoid formation of such piping in pouring ingots. Anotherobject of the invention is to provide for continuous pouring of ingots,using conventional open-top ingot molds.

In accordance with this invention, biiey stated, molds are arranged in arow and are connected together at their sprues by inclined runners. Oncea mold is filled, liquid metal is caused to tiow over its sprue to feedshrinkage therein, While the excess metal over Ithat required to feedshrinkage is directed by the runner into a next mold. More particularly,conventional yopen-top ingot molds are carried on cars moved along aninclined track leading up to the pouring station. A refractory coveringis placed on top of the molds to form a continuous runner extending thelength of the train, with sprues opening from the runner into the moldcavity. Metal is then poured in the runner adjacent to the upper end ofits incline to lill molds as they are moved to lthe pouring point, andfeed shrinkage in a lled mold as it moves beneath the pouring point.

Pouring is preferably continuous, but the first mold is not moved frombeneath the ladle immediately upon being lled. Instead, metal is pouredor caused to ow over the associated sprue for a 'substantial length oftime thereafter, the overflow being directed by the runner to ll afollowing mold. The mold movement may be continuous, but any given moldshould be tilled before its arrival at the pouring point so that 'thereis an opportunity to feed shrinkage from the runner before the moldmoves Ibeyond the pouring point. In this way, an adequate supply ofliquid metal for feeding shrinkage in the mold proper is not onlyassured, but heat is supplied to the metal in a sprue opening so as toprevent premature freezing of metal at the sprue.

Other features yof the invention will be in part apparent from and inpart pointed out in the following detail description taken in connectionwith the accompanying drawings, in which:

Fig. l is a top plan view illustrating the invention as employed inpouring ingots; and,

Fig. 2 is a side elevation of the apparatus shown in Fig. l, parts beingshown in section.

Referring now to the drawings, molds 1 lare arranged in a row forrelative movement with respect to a pouring station. In the illustratedembodiment, the molds are carried by trucks 3, which are coupledtogether at 7 in uniformly spaced relationship, and the trucks are moved'along a track 5 in the direction indicated by a suitable de- PatentedJuly 23, 1957 ICC Vvice (not shown). YThe molds i1 iareconventionalingot Aeachfmember'functions toschannel-:tlow-of liquid metal lbetweenWalls-'17,"and-atfthe ends of the jgroove yare recesses 19, which for-m'relatively-'smallsprueeopenings for filling the molds.

In operation, the covers 13 are `arranged in -endabutting relationshipon ltop of the molds, eac-h member 13 reaching from the `center of onemold to the center of an adjoining mold. The molds are thus closedexcept for relatively small sprue openings 19 which are connectedtogether by a continuous runner extending the length of the train. Metalis poured into the runner from a ladle 21 or other source of liquidmetal located at a point adjacent the upper end of the inclined part ofthe track.

At the beginning of a pouring operation, |the initial mold is movedgenerally beneath the ladle 21 and filled. When lled, the mold is notimmediately moved from beneath the ladle, ibut liquid is all-owed to lowont-o or over the associated sprue While rthe metal in this initial moldcools and sets. Consequently, a continuous supply of hot liquid metal ispresent at the sprue to feed whatever shiinkage occurs, the excess overthat required to feed shrinkage being -directed by the runner 15 into afollowing mold. After the possibility of shrinkage at the iirst mold haspassed, the molds may be moved continuously as a unit until the pouringoperation yis completed.

During movement of the molds, met-al continues to ow from the ladle, butit will be apparent that the molds are filled before they reach theladle. In other words, a given mold arriving at the pouring station 23has been filled previously from the runner 15, and shrinkage is inprogress; however, such shrinkage is adequately fed from the runner asthe mold moves to and beneath the ladle. As the last -mold in the trainapproaches the ladle, the pouring may be stopped, in which event someshrinkage will loccur in the iinal ingot, but that ingot may beremelted. After the pouring operation has been completed, the covers 13are removed from the molds to permit Withdrawal lof the ingots.

The rate of ow at 23 and lthe rate of mold movement are controlledrelative to one another 4so as to maintain a stabilized conditionVduring the pouring operation; and both metal ow and mold movement `areadjusted relative to the time required for the metal in a filled mold tofreeze. For example, the time required for the metal in a mold to setafter lling, the time required to lill mold C-1 and feed shrinkage atB-l (as determined by the rate of oW at 23), fand the time required formold C-l to move to the ladle yafter filling (as determined by the speedof the trucks 3), should all be approximately equal.

From the foregoing description, it is -apparent that those skilled inthe art will understand the structure, methods, function, and mode ofoperation Aof the invention herein disclosed, and appreciate theadvantages thereof. It may be noted, that Whereas the invention itsdescribed in particular as utilized in 'the pouring Iof ingots, theinvention may also be used in pouring other types of castings, andreference is made lby my copending application entitled Manufacture ofCastings, Serial No. 333,316, filed January 26, 1953.

Although [one embodiment has been disclosed in detail, itis to beunderstood that the'invention is Ynot limited thereto, but the drawingsand description thereof are to be understood as being merelyillustrative.

It is realized that other modifications and variations will presentvthemselves -t-o those skilled in the art without departing from thespirit lof this invention or the scope Y thereof as set forth in theappended claims.

Having *thus described the invention, what is claimed and Idesired to besecured by Letters Patent is:

l. Apparatus for lling conventional open-top ingot molds comprising atrack inclined to a pouring station, a plurality of cars on said track,each of said cars carrying an ingot mold, and re-usable cover sectionslaid in endabutting relationship on top of and lbridging adjacent molds,said cover sections 'being shaped to form an open -trough extendinglengthwise of the rtrain with sprues op ening therefrom into said moldsat vthe abutting ends of said cover sections. Y Y

4 2. A re-usable cover section for use in pouring ingots withconventional open-top ingot molds which are carried on -a train of cars,said cover section being formed of refractory material and being of `alength suicient to extend between the centers of adjacent cars and -of awidth `suiicient -to cover the top of an ingot mold, said cover sectionhaving a groove extending lengthwise from end toend, and a sprue-formingrecess extending across one end thereof from said groove.

References Cited in the file of this patent VUNITED STATES PATENTS521,449 Adams June 19, 1894 735,303 Sauver Aug. 4, 1903 1,454,741 Howardet al. May 8, 1923 1,572,866 McKune Feb. 9, 1926 2,326,164 Payne Aug.10, 1943

